1. Field of the Invention
The present invention relates to a magnetic head assembly in a magnetic disk apparatus.
2. Description of the Related Art
A magnetic disk apparatus comprises a plurality of coaxially arranged magnetic disk and a plurality of magnetic head assemblies operating in cooperation with the magnetic disks. Each magnetic head assembly includes two magnetic heads inserted in a gap between the adjacent magnetic disks, with one magnetic head having access to the lower surface of the upper magnetic disk and the other magnetic head having access to the upper surface of the lower magnetic disk. The magnetic heads are carried by spring arms, respectively and a pair of spring arms are in turn supported by a rigid head arm that is mounted on an actuator spindle. The actuator spindle can be rotated to move the head arm and the spring arms so that the magnetic heads move generally radially of the magnetic disks, i.e., across the tracks of the magnetic disks.
There are two known methods of mounting two spring arms to the head arm. In the first method, one spring arm is attached to the upper surface of the head arm and the other spring arm is attached to the lower surface of the head arm; and in the second method, two spring arms are attached together to the upper surface of the head arm. These features are described in, for example, Japanese Unexamined Patent Publication (Kokai) No. 2-235272, No. 3-144978 and No. 4-137284. In these prior arts, two spring arms are fixed to the head arm by screws.
In contemporary magnetic disk apparatuses, there is a demand for the gap between the adjacent magnetic disks to be reduced as small as possible so as to increase the number of the magnetic disks equipped in the apparatus. It is believed that it is possible to reduce the gap between the adjacent magnetic disks according to the above described second method. However, there are problems in the-prior art, which uses screws to attach two spring arms to the head arm in that it is difficult to tighten the screws in the gap between the adjacent magnetic disks. It is also difficult to automatically assemble the magnetic head assemblies using screws.
Japanese Unexamined Utility Model Publication (Kokai) No. 64-12267 discloses a magnetic disk apparatus in which supporting elements are fixed to the spring arms, respectively. One supporting element is engaged in a hole provided in the head arm from one side thereof with an associated spring arm located on the outside of the supporting element and the other supporting element is engaged in a hole provided in the head arm from the other side thereof with an associated spring arm located on the outside of the supporting element. Press means are then forcibly inserted in the supporting elements thereby causing the supporting element to be permanently deformed so as to bite in the head arm.
This prior art does not use screws for fixing two spring arms to the head arm. However, this prior art does not satisfy a demand that the gap between the adjacent magnetic disks be reduced as small as possible, as this relates to the above described first method and because the supporting elements increase the thickness of the magnetic head assembly.